1 /* zlib.h -- interface of the 'zlib' general purpose compression library
2   version 1.1.4, March 11th, 2002
3 
4   Copyright (C) 1995-2002 Jean-loup Gailly and Mark Adler
5 
6   This software is provided 'as-is', without any express or implied
7   warranty.  In no event will the authors be held liable for any damages
8   arising from the use of this software.
9 
10   Permission is granted to anyone to use this software for any purpose,
11   including commercial applications, and to alter it and redistribute it
12   freely, subject to the following restrictions:
13 
14   1. The origin of this software must not be misrepresented; you must not
15      claim that you wrote the original software. If you use this software
16      in a product, an acknowledgment in the product documentation would be
17      appreciated but is not required.
18   2. Altered source versions must be plainly marked as such, and must not be
19      misrepresented as being the original software.
20   3. This notice may not be removed or altered from any source distribution.
21 
22   Jean-loup Gailly        Mark Adler
23   jloup@gzip.org          madler@alumni.caltech.edu
24 
25 
26   The data format used by the zlib library is described by RFCs (Request for
27   Comments) 1950 to 1952 in the files ftp://ds.internic.net/rfc/rfc1950.txt
28   (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
29 */
30 
31 #if defined(__ARMCC__) || defined(__CC_ARM)
32 /* Ultra ugly hack that convinces RVCT to use the systems zlib */
33 #include <stdapis/zlib.h>
34 #else /* defined(__ARMCC__) || defined(__CC_ARM) */
35 
36 #ifndef _ZLIB_H
37 #define _ZLIB_H
38 
39 #include "zconf.h"
40 
41 #ifdef __cplusplus
42 extern "C" {
43 #endif
44 
45 #define ZLIB_VERSION "1.1.4"
46 
47 /*
48      The 'zlib' compression library provides in-memory compression and
49   decompression functions, including integrity checks of the uncompressed
50   data.  This version of the library supports only one compression method
51   (deflation) but other algorithms will be added later and will have the same
52   stream interface.
53 
54      Compression can be done in a single step if the buffers are large
55   enough (for example if an input file is mmap'ed), or can be done by
56   repeated calls of the compression function.  In the latter case, the
57   application must provide more input and/or consume the output
58   (providing more output space) before each call.
59 
60      The library also supports reading and writing files in gzip (.gz) format
61   with an interface similar to that of stdio.
62 
63      The library does not install any signal handler. The decoder checks
64   the consistency of the compressed data, so the library should never
65   crash even in case of corrupted input.
66 */
67 
68 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
69 typedef void   (*free_func)  OF((voidpf opaque, voidpf address));
70 
71 struct internal_state;
72 
73 typedef struct z_stream_s {
74     Bytef    *next_in;  /* next input byte */
75     uInt     avail_in;  /* number of bytes available at next_in */
76     uLong    total_in;  /* total nb of input bytes read so far */
77 
78     Bytef    *next_out; /* next output byte should be put there */
79     uInt     avail_out; /* remaining free space at next_out */
80     uLong    total_out; /* total nb of bytes output so far */
81 
82     char     *msg;      /* last error message, NULL if no error */
83     struct internal_state FAR *state; /* not visible by applications */
84 
85     alloc_func zalloc;  /* used to allocate the internal state */
86     free_func  zfree;   /* used to free the internal state */
87     voidpf     opaque;  /* private data object passed to zalloc and zfree */
88 
89     int     data_type;  /* best guess about the data type: ascii or binary */
90     uLong   adler;      /* adler32 value of the uncompressed data */
91     uLong   reserved;   /* reserved for future use */
92 } z_stream;
93 
94 typedef z_stream FAR *z_streamp;
95 
96 /*
97    The application must update next_in and avail_in when avail_in has
98    dropped to zero. It must update next_out and avail_out when avail_out
99    has dropped to zero. The application must initialize zalloc, zfree and
100    opaque before calling the init function. All other fields are set by the
101    compression library and must not be updated by the application.
102 
103    The opaque value provided by the application will be passed as the first
104    parameter for calls of zalloc and zfree. This can be useful for custom
105    memory management. The compression library attaches no meaning to the
106    opaque value.
107 
108    zalloc must return Z_NULL if there is not enough memory for the object.
109    If zlib is used in a multi-threaded application, zalloc and zfree must be
110    thread safe.
111 
112    On 16-bit systems, the functions zalloc and zfree must be able to allocate
113    exactly 65536 bytes, but will not be required to allocate more than this
114    if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
115    pointers returned by zalloc for objects of exactly 65536 bytes *must*
116    have their offset normalized to zero. The default allocation function
117    provided by this library ensures this (see zutil.c). To reduce memory
118    requirements and avoid any allocation of 64K objects, at the expense of
119    compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
120 
121    The fields total_in and total_out can be used for statistics or
122    progress reports. After compression, total_in holds the total size of
123    the uncompressed data and may be saved for use in the decompressor
124    (particularly if the decompressor wants to decompress everything in
125    a single step).
126 */
127 
128                         /* constants */
129 
130 #define Z_NO_FLUSH      0
131 #define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */
132 #define Z_SYNC_FLUSH    2
133 #define Z_FULL_FLUSH    3
134 #define Z_FINISH        4
135 /* Allowed flush values; see deflate() below for details */
136 
137 #define Z_OK            0
138 #define Z_STREAM_END    1
139 #define Z_NEED_DICT     2
140 #define Z_ERRNO        (-1)
141 #define Z_STREAM_ERROR (-2)
142 #define Z_DATA_ERROR   (-3)
143 #define Z_MEM_ERROR    (-4)
144 #define Z_BUF_ERROR    (-5)
145 #define Z_VERSION_ERROR (-6)
146 /* Return codes for the compression/decompression functions. Negative
147  * values are errors, positive values are used for special but normal events.
148  */
149 
150 #define Z_NO_COMPRESSION         0
151 #define Z_BEST_SPEED             1
152 #define Z_BEST_COMPRESSION       9
153 #define Z_DEFAULT_COMPRESSION  (-1)
154 /* compression levels */
155 
156 #define Z_FILTERED            1
157 #define Z_HUFFMAN_ONLY        2
158 #define Z_DEFAULT_STRATEGY    0
159 /* compression strategy; see deflateInit2() below for details */
160 
161 #define Z_BINARY   0
162 #define Z_ASCII    1
163 #define Z_UNKNOWN  2
164 /* Possible values of the data_type field */
165 
166 #define Z_DEFLATED   8
167 /* The deflate compression method (the only one supported in this version) */
168 
169 #define Z_NULL  0  /* for initializing zalloc, zfree, opaque */
170 
171 
172                         /* basic functions */
173 
174 /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
175    If the first character differs, the library code actually used is
176    not compatible with the zlib.h header file used by the application.
177    This check is automatically made by deflateInit and inflateInit.
178  */
179 
180 /*
181 ZEXTERN(int)  deflateInit OF((z_streamp strm, int level));
182 
183      Initializes the internal stream state for compression. The fields
184    zalloc, zfree and opaque must be initialized before by the caller.
185    If zalloc and zfree are set to Z_NULL, deflateInit updates them to
186    use default allocation functions.
187 
188      The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
189    1 gives best speed, 9 gives best compression, 0 gives no compression at
190    all (the input data is simply copied a block at a time).
191    Z_DEFAULT_COMPRESSION requests a default compromise between speed and
192    compression (currently equivalent to level 6).
193 
194      deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
195    enough memory, Z_STREAM_ERROR if level is not a valid compression level,
196    Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
197    with the version assumed by the caller (ZLIB_VERSION).
198    msg is set to null if there is no error message.  deflateInit does not
199    perform any compression: this will be done by deflate().
200 */
201 
202 
203 /*
204     deflate compresses as much data as possible, and stops when the input
205   buffer becomes empty or the output buffer becomes full. It may introduce some
206   output latency (reading input without producing any output) except when
207   forced to flush.
208 
209     The detailed semantics are as follows. deflate performs one or both of the
210   following actions:
211 
212   - Compress more input starting at next_in and update next_in and avail_in
213     accordingly. If not all input can be processed (because there is not
214     enough room in the output buffer), next_in and avail_in are updated and
215     processing will resume at this point for the next call of deflate().
216 
217   - Provide more output starting at next_out and update next_out and avail_out
218     accordingly. This action is forced if the parameter flush is non zero.
219     Forcing flush frequently degrades the compression ratio, so this parameter
220     should be set only when necessary (in interactive applications).
221     Some output may be provided even if flush is not set.
222 
223   Before the call of deflate(), the application should ensure that at least
224   one of the actions is possible, by providing more input and/or consuming
225   more output, and updating avail_in or avail_out accordingly; avail_out
226   should never be zero before the call. The application can consume the
227   compressed output when it wants, for example when the output buffer is full
228   (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK
229   and with zero avail_out, it must be called again after making room in the
230   output buffer because there might be more output pending.
231 
232     If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
233   flushed to the output buffer and the output is aligned on a byte boundary, so
234   that the decompressor can get all input data available so far. (In particular
235   avail_in is zero after the call if enough output space has been provided
236   before the call.)  Flushing may degrade compression for some compression
237   algorithms and so it should be used only when necessary.
238 
239     If flush is set to Z_FULL_FLUSH, all output is flushed as with
240   Z_SYNC_FLUSH, and the compression state is reset so that decompression can
241   restart from this point if previous compressed data has been damaged or if
242   random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
243   the compression.
244 
245     If deflate returns with avail_out == 0, this function must be called again
246   with the same value of the flush parameter and more output space (updated
247   avail_out), until the flush is complete (deflate returns with non-zero
248   avail_out).
249 
250     If the parameter flush is set to Z_FINISH, pending input is processed,
251   pending output is flushed and deflate returns with Z_STREAM_END if there
252   was enough output space; if deflate returns with Z_OK, this function must be
253   called again with Z_FINISH and more output space (updated avail_out) but no
254   more input data, until it returns with Z_STREAM_END or an error. After
255   deflate has returned Z_STREAM_END, the only possible operations on the
256   stream are deflateReset or deflateEnd.
257 
258     Z_FINISH can be used immediately after deflateInit if all the compression
259   is to be done in a single step. In this case, avail_out must be at least
260   0.1% larger than avail_in plus 12 bytes.  If deflate does not return
261   Z_STREAM_END, then it must be called again as described above.
262 
263     deflate() sets strm->adler to the adler32 checksum of all input read
264   so far (that is, total_in bytes).
265 
266     deflate() may update data_type if it can make a good guess about
267   the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered
268   binary. This field is only for information purposes and does not affect
269   the compression algorithm in any manner.
270 
271     deflate() returns Z_OK if some progress has been made (more input
272   processed or more output produced), Z_STREAM_END if all input has been
273   consumed and all output has been produced (only when flush is set to
274   Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
275   if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible
276   (for example avail_in or avail_out was zero).
277 */
278 
279 
280 /*
281      All dynamically allocated data structures for this stream are freed.
282    This function discards any unprocessed input and does not flush any
283    pending output.
284 
285      deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
286    stream state was inconsistent, Z_DATA_ERROR if the stream was freed
287    prematurely (some input or output was discarded). In the error case,
288    msg may be set but then points to a static string (which must not be
289    deallocated).
290 */
291 
292 
293 /*
294 ZEXTERN(int)  inflateInit OF((z_streamp strm));
295 
296      Initializes the internal stream state for decompression. The fields
297    next_in, avail_in, zalloc, zfree and opaque must be initialized before by
298    the caller. If next_in is not Z_NULL and avail_in is large enough (the exact
299    value depends on the compression method), inflateInit determines the
300    compression method from the zlib header and allocates all data structures
301    accordingly; otherwise the allocation will be deferred to the first call of
302    inflate.  If zalloc and zfree are set to Z_NULL, inflateInit updates them to
303    use default allocation functions.
304 
305      inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
306    memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
307    version assumed by the caller.  msg is set to null if there is no error
308    message. inflateInit does not perform any decompression apart from reading
309    the zlib header if present: this will be done by inflate().  (So next_in and
310    avail_in may be modified, but next_out and avail_out are unchanged.)
311 */
312 
313 
314 ZEXTERN(int) inflate OF((z_streamp strm, int flush));
315 /*
316     inflate decompresses as much data as possible, and stops when the input
317   buffer becomes empty or the output buffer becomes full. It may some
318   introduce some output latency (reading input without producing any output)
319   except when forced to flush.
320 
321   The detailed semantics are as follows. inflate performs one or both of the
322   following actions:
323 
324   - Decompress more input starting at next_in and update next_in and avail_in
325     accordingly. If not all input can be processed (because there is not
326     enough room in the output buffer), next_in is updated and processing
327     will resume at this point for the next call of inflate().
328 
329   - Provide more output starting at next_out and update next_out and avail_out
330     accordingly.  inflate() provides as much output as possible, until there
331     is no more input data or no more space in the output buffer (see below
332     about the flush parameter).
333 
334   Before the call of inflate(), the application should ensure that at least
335   one of the actions is possible, by providing more input and/or consuming
336   more output, and updating the next_* and avail_* values accordingly.
337   The application can consume the uncompressed output when it wants, for
338   example when the output buffer is full (avail_out == 0), or after each
339   call of inflate(). If inflate returns Z_OK and with zero avail_out, it
340   must be called again after making room in the output buffer because there
341   might be more output pending.
342 
343     If the parameter flush is set to Z_SYNC_FLUSH, inflate flushes as much
344   output as possible to the output buffer. The flushing behavior of inflate is
345   not specified for values of the flush parameter other than Z_SYNC_FLUSH
346   and Z_FINISH, but the current implementation actually flushes as much output
347   as possible anyway.
348 
349     inflate() should normally be called until it returns Z_STREAM_END or an
350   error. However if all decompression is to be performed in a single step
351   (a single call of inflate), the parameter flush should be set to
352   Z_FINISH. In this case all pending input is processed and all pending
353   output is flushed; avail_out must be large enough to hold all the
354   uncompressed data. (The size of the uncompressed data may have been saved
355   by the compressor for this purpose.) The next operation on this stream must
356   be inflateEnd to deallocate the decompression state. The use of Z_FINISH
357   is never required, but can be used to inform inflate that a faster routine
358   may be used for the single inflate() call.
359 
360      If a preset dictionary is needed at this point (see inflateSetDictionary
361   below), inflate sets strm-adler to the adler32 checksum of the
362   dictionary chosen by the compressor and returns Z_NEED_DICT; otherwise
363   it sets strm->adler to the adler32 checksum of all output produced
364   so far (that is, total_out bytes) and returns Z_OK, Z_STREAM_END or
365   an error code as described below. At the end of the stream, inflate()
366   checks that its computed adler32 checksum is equal to that saved by the
367   compressor and returns Z_STREAM_END only if the checksum is correct.
368 
369     inflate() returns Z_OK if some progress has been made (more input processed
370   or more output produced), Z_STREAM_END if the end of the compressed data has
371   been reached and all uncompressed output has been produced, Z_NEED_DICT if a
372   preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
373   corrupted (input stream not conforming to the zlib format or incorrect
374   adler32 checksum), Z_STREAM_ERROR if the stream structure was inconsistent
375   (for example if next_in or next_out was NULL), Z_MEM_ERROR if there was not
376   enough memory, Z_BUF_ERROR if no progress is possible or if there was not
377   enough room in the output buffer when Z_FINISH is used. In the Z_DATA_ERROR
378   case, the application may then call inflateSync to look for a good
379   compression block.
380 */
381 
382 
383 ZEXTERN(int)  inflateEnd OF((z_streamp strm));
384 /*
385      All dynamically allocated data structures for this stream are freed.
386    This function discards any unprocessed input and does not flush any
387    pending output.
388 
389      inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
390    was inconsistent. In the error case, msg may be set but then points to a
391    static string (which must not be deallocated).
392 */
393 
394                         /* Advanced functions */
395 
396 /*
397     The following functions are needed only in some special applications.
398 */
399 
400 /*
401 ZEXTERN(int)  deflateInit2 OF((z_streamp strm,
402                                      int  level,
403                                      int  method,
404                                      int  windowBits,
405                                      int  memLevel,
406                                      int  strategy));
407 
408      This is another version of deflateInit with more compression options. The
409    fields next_in, zalloc, zfree and opaque must be initialized before by
410    the caller.
411 
412      The method parameter is the compression method. It must be Z_DEFLATED in
413    this version of the library.
414 
415      The windowBits parameter is the base two logarithm of the window size
416    (the size of the history buffer).  It should be in the range 8..15 for this
417    version of the library. Larger values of this parameter result in better
418    compression at the expense of memory usage. The default value is 15 if
419    deflateInit is used instead.
420 
421      The memLevel parameter specifies how much memory should be allocated
422    for the internal compression state. memLevel=1 uses minimum memory but
423    is slow and reduces compression ratio; memLevel=9 uses maximum memory
424    for optimal speed. The default value is 8. See zconf.h for total memory
425    usage as a function of windowBits and memLevel.
426 
427      The strategy parameter is used to tune the compression algorithm. Use the
428    value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
429    filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman encoding only (no
430    string match).  Filtered data consists mostly of small values with a
431    somewhat random distribution. In this case, the compression algorithm is
432    tuned to compress them better. The effect of Z_FILTERED is to force more
433    Huffman coding and less string matching; it is somewhat intermediate
434    between Z_DEFAULT and Z_HUFFMAN_ONLY. The strategy parameter only affects
435    the compression ratio but not the correctness of the compressed output even
436    if it is not set appropriately.
437 
438       deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
439    memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid
440    method). msg is set to null if there is no error message.  deflateInit2 does
441    not perform any compression: this will be done by deflate().
442 */
443 
444 /*
445      Initializes the compression dictionary from the given byte sequence
446    without producing any compressed output. This function must be called
447    immediately after deflateInit, deflateInit2 or deflateReset, before any
448    call of deflate. The compressor and decompressor must use exactly the same
449    dictionary (see inflateSetDictionary).
450 
451      The dictionary should consist of strings (byte sequences) that are likely
452    to be encountered later in the data to be compressed, with the most commonly
453    used strings preferably put towards the end of the dictionary. Using a
454    dictionary is most useful when the data to be compressed is short and can be
455    predicted with good accuracy; the data can then be compressed better than
456    with the default empty dictionary.
457 
458      Depending on the size of the compression data structures selected by
459    deflateInit or deflateInit2, a part of the dictionary may in effect be
460    discarded, for example if the dictionary is larger than the window size in
461    deflate or deflate2. Thus the strings most likely to be useful should be
462    put at the end of the dictionary, not at the front.
463 
464      Upon return of this function, strm->adler is set to the Adler32 value
465    of the dictionary; the decompressor may later use this value to determine
466    which dictionary has been used by the compressor. (The Adler32 value
467    applies to the whole dictionary even if only a subset of the dictionary is
468    actually used by the compressor.)
469 
470      deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
471    parameter is invalid (such as NULL dictionary) or the stream state is
472    inconsistent (for example if deflate has already been called for this stream
473    or if the compression method is bsort). deflateSetDictionary does not
474    perform any compression: this will be done by deflate().
475 */
476 
477 /*
478      Sets the destination stream as a complete copy of the source stream.
479 
480      This function can be useful when several compression strategies will be
481    tried, for example when there are several ways of pre-processing the input
482    data with a filter. The streams that will be discarded should then be freed
483    by calling deflateEnd.  Note that deflateCopy duplicates the internal
484    compression state which can be quite large, so this strategy is slow and
485    can consume lots of memory.
486 
487      deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
488    enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
489    (such as zalloc being NULL). msg is left unchanged in both source and
490    destination.
491 */
492 
493 /*
494      This function is equivalent to deflateEnd followed by deflateInit,
495    but does not free and reallocate all the internal compression state.
496    The stream will keep the same compression level and any other attributes
497    that may have been set by deflateInit2.
498 
499       deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
500    stream state was inconsistent (such as zalloc or state being NULL).
501 */
502 
503 /*
504      Dynamically update the compression level and compression strategy.  The
505    interpretation of level and strategy is as in deflateInit2.  This can be
506    used to switch between compression and straight copy of the input data, or
507    to switch to a different kind of input data requiring a different
508    strategy. If the compression level is changed, the input available so far
509    is compressed with the old level (and may be flushed); the new level will
510    take effect only at the next call of deflate().
511 
512      Before the call of deflateParams, the stream state must be set as for
513    a call of deflate(), since the currently available input may have to
514    be compressed and flushed. In particular, strm->avail_out must be non-zero.
515 
516      deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
517    stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR
518    if strm->avail_out was zero.
519 */
520 
521 /*
522 ZEXTERN(int)  inflateInit2 OF((z_streamp strm,
523                                      int  windowBits));
524 
525      This is another version of inflateInit with an extra parameter. The
526    fields next_in, avail_in, zalloc, zfree and opaque must be initialized
527    before by the caller.
528 
529      The windowBits parameter is the base two logarithm of the maximum window
530    size (the size of the history buffer).  It should be in the range 8..15 for
531    this version of the library. The default value is 15 if inflateInit is used
532    instead. If a compressed stream with a larger window size is given as
533    input, inflate() will return with the error code Z_DATA_ERROR instead of
534    trying to allocate a larger window.
535 
536       inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
537    memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative
538    memLevel). msg is set to null if there is no error message.  inflateInit2
539    does not perform any decompression apart from reading the zlib header if
540    present: this will be done by inflate(). (So next_in and avail_in may be
541    modified, but next_out and avail_out are unchanged.)
542 */
543 
544 /*
545      Initializes the decompression dictionary from the given uncompressed byte
546    sequence. This function must be called immediately after a call of inflate
547    if this call returned Z_NEED_DICT. The dictionary chosen by the compressor
548    can be determined from the Adler32 value returned by this call of
549    inflate. The compressor and decompressor must use exactly the same
550    dictionary (see deflateSetDictionary).
551 
552      inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
553    parameter is invalid (such as NULL dictionary) or the stream state is
554    inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
555    expected one (incorrect Adler32 value). inflateSetDictionary does not
556    perform any decompression: this will be done by subsequent calls of
557    inflate().
558 */
559 
560 /*
561     Skips invalid compressed data until a full flush point (see above the
562   description of deflate with Z_FULL_FLUSH) can be found, or until all
563   available input is skipped. No output is provided.
564 
565     inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
566   if no more input was provided, Z_DATA_ERROR if no flush point has been found,
567   or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
568   case, the application may save the current current value of total_in which
569   indicates where valid compressed data was found. In the error case, the
570   application may repeatedly call inflateSync, providing more input each time,
571   until success or end of the input data.
572 */
573 
574 ZEXTERN(int)  inflateReset OF((z_streamp strm));
575 /*
576      This function is equivalent to inflateEnd followed by inflateInit,
577    but does not free and reallocate all the internal decompression state.
578    The stream will keep attributes that may have been set by inflateInit2.
579 
580       inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
581    stream state was inconsistent (such as zalloc or state being NULL).
582 */
583 
584 
585                         /* utility functions */
586 
587 /*
588      The following utility functions are implemented on top of the
589    basic stream-oriented functions. To simplify the interface, some
590    default options are assumed (compression level and memory usage,
591    standard memory allocation functions). The source code of these
592    utility functions can easily be modified if you need special options.
593 */
594 
595 /*
596      Compresses the source buffer into the destination buffer.  sourceLen is
597    the byte length of the source buffer. Upon entry, destLen is the total
598    size of the destination buffer, which must be at least 0.1% larger than
599    sourceLen plus 12 bytes. Upon exit, destLen is the actual size of the
600    compressed buffer.
601      This function can be used to compress a whole file at once if the
602    input file is mmap'ed.
603      compress returns Z_OK if success, Z_MEM_ERROR if there was not
604    enough memory, Z_BUF_ERROR if there was not enough room in the output
605    buffer.
606 */
607 
608 /*
609      Compresses the source buffer into the destination buffer. The level
610    parameter has the same meaning as in deflateInit.  sourceLen is the byte
611    length of the source buffer. Upon entry, destLen is the total size of the
612    destination buffer, which must be at least 0.1% larger than sourceLen plus
613    12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
614 
615      compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
616    memory, Z_BUF_ERROR if there was not enough room in the output buffer,
617    Z_STREAM_ERROR if the level parameter is invalid.
618 */
619 
620 /*
621      Decompresses the source buffer into the destination buffer.  sourceLen is
622    the byte length of the source buffer. Upon entry, destLen is the total
623    size of the destination buffer, which must be large enough to hold the
624    entire uncompressed data. (The size of the uncompressed data must have
625    been saved previously by the compressor and transmitted to the decompressor
626    by some mechanism outside the scope of this compression library.)
627    Upon exit, destLen is the actual size of the compressed buffer.
628      This function can be used to decompress a whole file at once if the
629    input file is mmap'ed.
630 
631      uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
632    enough memory, Z_BUF_ERROR if there was not enough room in the output
633    buffer, or Z_DATA_ERROR if the input data was corrupted.
634 */
635 
636 
637 /*
638      Opens a gzip (.gz) file for reading or writing. The mode parameter
639    is as in fopen ("rb" or "wb") but can also include a compression level
640    ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for
641    Huffman only compression as in "wb1h". (See the description
642    of deflateInit2 for more information about the strategy parameter.)
643 
644      gzopen can be used to read a file which is not in gzip format; in this
645    case gzread will directly read from the file without decompression.
646 
647      gzopen returns NULL if the file could not be opened or if there was
648    insufficient memory to allocate the (de)compression state; errno
649    can be checked to distinguish the two cases (if errno is zero, the
650    zlib error is Z_MEM_ERROR).  */
651 
652 /*
653      gzdopen() associates a gzFile with the file descriptor fd.  File
654    descriptors are obtained from calls like open, dup, creat, pipe or
655    fileno (in the file has been previously opened with fopen).
656    The mode parameter is as in gzopen.
657      The next call of gzclose on the returned gzFile will also close the
658    file descriptor fd, just like fclose(fdopen(fd), mode) closes the file
659    descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode).
660      gzdopen returns NULL if there was insufficient memory to allocate
661    the (de)compression state.
662 */
663 
664 /*
665      Dynamically update the compression level or strategy. See the description
666    of deflateInit2 for the meaning of these parameters.
667      gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
668    opened for writing.
669 */
670 
671 /*
672      Reads the given number of uncompressed bytes from the compressed file.
673    If the input file was not in gzip format, gzread copies the given number
674    of bytes into the buffer.
675      gzread returns the number of uncompressed bytes actually read (0 for
676    end of file, -1 for error). */
677 
678 /*
679      Writes the given number of uncompressed bytes into the compressed file.
680    gzwrite returns the number of uncompressed bytes actually written
681    (0 in case of error).
682 */
683 
684 /*
685      Converts, formats, and writes the args to the compressed file under
686    control of the format string, as in fprintf. gzprintf returns the number of
687    uncompressed bytes actually written (0 in case of error).
688 */
689 
690 /*
691       Writes the given null-terminated string to the compressed file, excluding
692    the terminating null character.
693       gzputs returns the number of characters written, or -1 in case of error.
694 */
695 
696 /*
697       Reads bytes from the compressed file until len-1 characters are read, or
698    a newline character is read and transferred to buf, or an end-of-file
699    condition is encountered.  The string is then terminated with a null
700    character.
701       gzgets returns buf, or Z_NULL in case of error.
702 */
703 
704 /*
705       Writes c, converted to an unsigned char, into the compressed file.
706    gzputc returns the value that was written, or -1 in case of error.
707 */
708 
709 /*
710       Reads one byte from the compressed file. gzgetc returns this byte
711    or -1 in case of end of file or error.
712 */
713 
714 /*
715      Flushes all pending output into the compressed file. The parameter
716    flush is as in the deflate() function. The return value is the zlib
717    error number (see function gzerror below). gzflush returns Z_OK if
718    the flush parameter is Z_FINISH and all output could be flushed.
719      gzflush should be called only when strictly necessary because it can
720    degrade compression.
721 */
722 
723 /*
724       Sets the starting position for the next gzread or gzwrite on the
725    given compressed file. The offset represents a number of bytes in the
726    uncompressed data stream. The whence parameter is defined as in lseek(2);
727    the value SEEK_END is not supported.
728      If the file is opened for reading, this function is emulated but can be
729    extremely slow. If the file is opened for writing, only forward seeks are
730    supported; gzseek then compresses a sequence of zeroes up to the new
731    starting position.
732 
733       gzseek returns the resulting offset location as measured in bytes from
734    the beginning of the uncompressed stream, or -1 in case of error, in
735    particular if the file is opened for writing and the new starting position
736    would be before the current position.
737 */
738 
739 /*
740      Rewinds the given file. This function is supported only for reading.
741 
742    gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
743 */
744 
745 /*
746      Returns the starting position for the next gzread or gzwrite on the
747    given compressed file. This position represents a number of bytes in the
748    uncompressed data stream.
749 
750    gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
751 */
752 
753 /*
754      Returns 1 when EOF has previously been detected reading the given
755    input stream, otherwise zero.
756 */
757 
758 /*
759      Flushes all pending output if necessary, closes the compressed file
760    and deallocates all the (de)compression state. The return value is the zlib
761    error number (see function gzerror below).
762 */
763 
764 /*
765      Returns the error message for the last error which occurred on the
766    given compressed file. errnum is set to zlib error number. If an
767    error occurred in the file system and not in the compression library,
768    errnum is set to Z_ERRNO and the application may consult errno
769    to get the exact error code.
770 */
771 
772                         /* checksum functions */
773 
774 /*
775      These functions are not related to compression but are exported
776    anyway because they might be useful in applications using the
777    compression library.
778 */
779 
780 ZEXTERN(uLong)  adler32 OF((uLong adler, const Bytef *buf, uInt len));
781 
782 /*
783      Update a running Adler-32 checksum with the bytes buf[0..len-1] and
784    return the updated checksum. If buf is NULL, this function returns
785    the required initial value for the checksum.
786    An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
787    much faster. Usage example:
788 
789      uLong adler = adler32(0L, Z_NULL, 0);
790 
791      while (read_buffer(buffer, length) != EOF) {
792        adler = adler32(adler, buffer, length);
793      }
794      if (adler != original_adler) error();
795 */
796 
797 /*
798      Update a running crc with the bytes buf[0..len-1] and return the updated
799    crc. If buf is NULL, this function returns the required initial value
800    for the crc. Pre- and post-conditioning (one's complement) is performed
801    within this function so it shouldn't be done by the application.
802    Usage example:
803 
804      uLong crc = crc32(0L, Z_NULL, 0);
805 
806      while (read_buffer(buffer, length) != EOF) {
807        crc = crc32(crc, buffer, length);
808      }
809      if (crc != original_crc) error();
810 */
811 
812 
813                         /* various hacks, don't look :) */
814 
815 /* deflateInit and inflateInit are macros to allow checking the zlib version
816  * and the compiler's view of z_stream:
817  */
818 ZEXTERN(int)  inflateInit2_ OF((z_streamp strm, int  windowBits,
819                                       const char *version, int stream_size));
820 #define deflateInit(strm, level) \
821         deflateInit_((strm), (level),       ZLIB_VERSION, sizeof(z_stream))
822 #define inflateInit(strm) \
823         inflateInit_((strm),                ZLIB_VERSION, sizeof(z_stream))
824 #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
825         deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
826                       (strategy),           ZLIB_VERSION, sizeof(z_stream))
827 #define inflateInit2(strm, windowBits) \
828         inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
829 
830 
831 #ifdef __cplusplus
832 }
833 #endif
834 
835 #endif /* _ZLIB_H */
836 
837 #endif /* defined(__ARMCC__) || defined(__CC_ARM) */
838